Speaking at the Belmont-Paul women’s equality national monument on the occasion of Equal Pay Day, President Obama called on Congress to pass legislation to address the issue of pay inequality, while also once again hinting at his preference to have Hillary Clinton be his successor.

Talking at the museum, which once used to house the National Women’s Party, the President specifically asked Congress to draft a bill that would ask employers to prove that any pay disparity at their company is not gender-based. Adding that he felt inspired by the movement for gender equality in different places — boardrooms, sports, politics — he stopped just short of endorsing his former Secretary of State. “I want [women] to be astonished that there was ever a time when women were vastly outnumbered in the boardroom or in Congress, or there was ever a time when a woman had never sat in the Oval Office,” he told the audience. Obama has not yet officially endorsed either Democratic candidate.

“I don’t know how long it will take to get there, but I know we’re getting closer to that day.” He added: “If we truly value fairness then America should be a level playing field.”